Dial-up service is a common method of Internet access. Dial-up service uses a dial-up modem through which a computer makes phone calls to an Internet service provider. The dial-up modem transforms digital data from the personal computer into an analog signal for transmission through a phone line, and conversely converts incoming analog signals into digital data for the personal computer. Dial-up service is known to be slow. For example, viewing web pages with multimedia content, such as graphical images, is often unacceptably slow.
Broadband access addresses this problem by providing higher digital data rates than dial-up service. A “DSL” (Digital Subscriber Line) involves upgrading the dial-up modem to a higher speed modem, known as a DSL modem, as well as using an upgraded modem device at the Internet Service Provider (ISP) premises, also known as the “central office.” The DSL approach uses existing copper wire, possibly upgraded along certain segments to increase its capacity to carry digitized information. Often the DSL access line is a spare telephone line that is already connected to the client location, such as a business or a residential unit, and the central office is owned and operated by the local telephone company. The data rates achievable by DSL are dependent on the distance between the client location and the central office, and range roughly between 100 kbps-1500 kbps. A DSL connection is commonly called a broadband access line. There are many client locations, e.g., residential units, that are too far away from a central office to have DSL service available.
Another broadband access scheme most commonly used with residential clients makes use of the coaxial cable that passes through a residential unit, for purposes of providing television signals to the home, “Cable TV”. A specialized modem, called a cable modem, is attached the coaxial cable inside the residential unit. The cable modem facilitates digital communication between the residential unit and facilities owned by the cable TV operator (often called a “Multiple Services Operator” (MSO)). The MSO is attached to the Internet, and thus becomes an Internet service provider for the residential unit. The coaxial cable entering a residential unit is typically shared with other residential units in close geographic proximity. Peak data rates on the order of approximately 2 million bits per second (Mbps) are possible with cable modems, with current service offerings.